Forgive this question if it is stupid, but I have a 1971 280SEL 4.5 with just under 200K miles on it. I am the second owner, it is a daily driver.

The engine and transmission are still in solid working order, but with the recent hikes in gas, I cannot afford to keep the car as the daily driver, not at 13 mpg that is.

So, I'm wondering if there is any way to repower the car with a diesel engine, and if so, what the approximate cost would be.

Like I said, I understand this may be a seriously naive question, but I'd really rather not give this car up.

John B.

you would most likely be better off selling her, and buying a car with a diesel motor.. you would spend and arm and leg to do it properly, and you still may never get all the bugs out..

Probably the most compatiable engine would be 300D from w115 - logic being 114's and 108's shared the same 6 cyl engine blocks for awhile, so there's a chance engine mounts and bell housings might fit the early 300D even though the 108 never had a diesel engine.

I know the w123 diesels wont fit 114/115's partly on account of the oil filter colliding with steering gear. Other problems can be position of the AC compressor that hangs underneath on w123's possibly interfering with 108 subframe. Driveshaft length is another issue you want to consider.

There was a shop somewhere in Texas (El Paso?) that tried to specialize in 5 cyl diesel conversions for 108's maybe 10-15 yrs ago..... They went broke without customer base and little demand at that time, but this proves it CAN be done. In depth search by telephone among Texas MB gurus can yield more info. I'd like to know more about this myself.


Rule is that gas to diesel is easy conversion, the opposite is more difficult.

I've read of this conversion being done in Germany. Might want to check out some German 108 sites as well as www.mobile.de (german Autotrader) and do soem research.

How badly do you want to drive a 108 car? How much ga$ would the cost of conversion buy?

How about a 116 300SD? You would retain (to some degree) the vintage looks and see 27mpg.

I went and looked at new, small 4 cylnder cars last year. Considered buying something practical, but couldn't do it. After old MBs for the last 10 years, its hard to give up the feeling these cars provide. Fillups hurt, but depreciation would hurt more, and MB safety is something to consider.

I still want a 450SEL. Bet mint examples go for peanuts this summer.

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'90 300SE 298k
-300K and it gets put into retirement.
'80 300D 255k Purchased new by family in 1980.

Had a:
1973 220 (gas)
1980 300SD
1992 400E

Yeah but understandably kingpin suspension long-time 108 owners can panic and suffer severe culture shock if they get stuck driving anything else that seems flimsy and feeble, like driving a sofa pillow in comparison. So even $3,000 - $5,000 up front for the conversion might be a bargain to keep an immaculate 108 on the road for another 1/2 million miles.

Fahrgewehr, what have you heard about this conversion being done in Germany? If it's possible at less than $7,000 for the whole ball of wax including the car, then it's something i'd like to explore for myself...... even knowing with my cobbling might be able to put it together at half that expense.

http://groups.google.com/group/alt.auto.mercedes/browse_thread/thread/30e4c7856c1d18f8/3c15a6a05a1dbb9c?q=diesel+w108&rnum=1&hl=en#3c15a6a05a1dbb9c

Read the post from Juergen. Same guy who runs the mbspy.com site. Might want to get in touch with him...he posts on the alt.auto.mercedes NG.

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'90 300SE 298k
-300K and it gets put into retirement.
'80 300D 255k Purchased new by family in 1980.

Had a:
1973 220 (gas)
1980 300SD
1992 400E

I have a 73 280SEL 4.5, daily driver, and the recent madness at the pumps DOES sting...hell, I work for a non-profit group, so imagine my pay scale! Still, I ain't giving it up...!

Ford Festivas Be Damned!

ah, before you take a wrench to it, find out if your state will let you register it. I am not aware of any that would permit the conversion. Having said that, it's a lot easier to just buy a deisel car. Also, I guess I should point out that you have a rather high MPG for that model. Mine came in at about 8 mpg when it was still on the road. -CTH

__________________
- cth350@gmail.com
http://www.111lakeside.com/

The advice others are giving here is good. I personally don't think conversions are a very good idea. You can buy a good solid daily driver diesel model for less than it would cost you to convert yours and you'll have both intact cars then. I bet if you put a 5 cylinder 300D engine in a 108 you would only pick up about 10 MPG anyway over the 13 you are now getting so the break-even on it would probably be on the order of 30-50K miles. Oh yeah, and by the way it will be SLOW since the 108 is heavier and less aerodynamic than the later chassis were.

I have seen one or two 108 diesel conversions for sale on eBay in the past too. Maybe watch there and see what shows up.

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Marty D.

2013 C300 4Matic
1984 BMW 733i
2013 Lincoln MKz

As does mine, but that's an inherent design flaw with certian drivers in a 4.5...

I can't drive it slow, and I can't accelerate slowly with it.

I'm calling it a design flaw because I could probably get 1.5-2x the milage with it if I drove more conservatively! Plus, not having an overdrive transmission makes the gas go that much quicker at the speeds this car was MADE for.

That having been said, I've only driven my 4.5 about 4 times in the last 4 months, as I have a company vehicle that I take home...

I do NOT want to fill my car up now, premium is about $3.30 a gallon here!

__________________
Current:
2021 Charger Scat Pack Widebody "Sinabee"
2018 Durango R/T

Previous:
1972 280SE 4.5
2014 Jeep Grand Cherokee Limited "Hefe", 1992 Jeep Cherokee Laredo "Jeepy", 2006 Charger R/T "Hemi"
1999 Chrysler 300M - RIP @ 221k

Well I **CAN** drive it in a manner that gets 8mpg, and it's a lot more fun too.... But on highway, it is about 13 mpg.

I hear what folks are saying about buying a second car, but it's been my experience that maintenance on the 280SEL is much less when it is driven regularly. I think it's (regretfully) time to sell and move on.

Thanks for the advice.

You could wait until 2009 when a Democratic president takes office, but that's a good 3.5 years away yet If you're looking to sell your 4.5, I'm sure someone here would jump on it if the price were right, especially if it's rust-free.

__________________
Current:
2021 Charger Scat Pack Widebody "Sinabee"
2018 Durango R/T

Previous:
1972 280SE 4.5
2014 Jeep Grand Cherokee Limited "Hefe", 1992 Jeep Cherokee Laredo "Jeepy", 2006 Charger R/T "Hemi"
1999 Chrysler 300M - RIP @ 221k

Is LPG available in the US? Many gas engined cars in Europe or getting converted because of the cost.

__________________
With best regards

Al